This invention relates to a mold box changing method for a concrete block molding machine used for automatically changing a mold box for shaping or forming concrete blocks. The present invention provides a method and an apparatus for changing a mold box for a concrete block molding machine.
Heretofore, there has been known a method for changing a mold box consisting of a plunger (male mold) and a mold (female mold) which mold box is used for shaping concrete blocks. Until recently, it was an ordinary practice that the plunger and the mold are merely suspended in their separated states and carried in a predetermined location in those states. Then, a worker(s) fixes the plunger and the mold directly to the machine body by tightening bolts and nuts or by suitable other means at appropriate spots. An inconvenience associated this practice is that the mold box itself is extremely heavy (for example, one set of the plunger and mold weighs about 400 to 600 kg.) and therefore, time and labor consuming work is required for changing the mold box and in addition, this type of work often involves danger. For this reason, power saving was recently demanded for the mold box changing work. In line with this demand, there was proposed an auxiliary apparatus for attaching such a mold box, as disclosed, for example, in Japanese Utility Model Publication No. 3-18161, which was previously filed by the present applicant. In this auxiliary apparatus, at least a mold box-to-be-changed (hereinafter simply called as the xe2x80x9cchangeable mold boxxe2x80x9d) or replaced with a new one is once retained by a support arm disposed on a machine body, the changeable mold box is then loaded on a carriage travelling on a rail laid in this side of the machine body and then it is mechanically fed to outside the machine body. However, this apparatus still has such a shortcoming that for changing the changeable mold box with a new mold box on the carriage, the changeable mold box is once discharged by a separate hoisting mechanism at an outlet position and thereafter, a new mold box is separately lowered, by a manual operation, to load on the carriage in a suspended fashion. That is, the carriage itself is moved by the action of the cylinder and the action of the auxiliary apparatus (support arm) is operatively connected to an elevating table which is elevated upward by a cylinder so as to support the mold box automatically. However, a plunger composing a part of the mold box and a press which is elevated downward from an upper location of the machine body must be carried out manually by tightening a bolt in a conventional manner.
In this way, the carriage itself is self-traveled by an electric motor or by the action of the cylinder, and the support arm of the auxiliary apparatus is rotationally projected inward by movement of said carriage through an operatively connecting mechanism, thereby automatically supporting a side surface of the mold box which is elevated upward by a receiver. On the other hand, however, the attachment work of the plunger located at an upper location of the mold box to a lower surface of the press within the machine body is made by a manual operation, that is, by manually tightening the bolt in the conventional manner. Moreover, the most serious problem involved is that the attachment work of the plunger (in one pair of female and male component elements composing the mold box) located in the upper location to the press is not yet automatically made and therefore, the worker is obliged to creep into the narrow interior of the molding machine every time the attachment work is required and manually tighten the bolt. Since this work is not only troublesome but also quite risky, it is demanded that the changing work of the mold box be made completely automatically.
It is most desirable that the work for separating the changeable mold box composed of a plunger and a mold from the machine body, releasing the support of the support arm, loading the mold box on the carriage, discharging the mold box from the carriage, and at the outside of the machine body, loading a new mold box in the place of the changeable mold box on the carriage is all made automatically in a consecutive manner.
In the appearance of so-called color blocks which are currently in fashion in view of their fancy appearance, a proper quantity of color material and common concrete material (base material) is filled into two material feed hoppers as a process for molding such color blocks. For molding blocks of a wide variety of kinds each in a small quantity of production as currently increasingly required, mold boxes prepared in conformity with the configurations of such blocks are required to be changed frequently (for example, about 10 to 15 times a day). Early realization of shortening of the time for changing the mold box and creation of an automatic mold box changing apparatus having reliable safety means are keenly demanded.
The present invention has been accomplished in view of the above.
It is, therefore, a general object of the present invention to provide a mold box changing method for a concrete block molding machine and an apparatus for carrying out the method, capable of obviating the shortcomings inherent in the prior art.
To achieve the above object, from one aspect of the present invention, there is essentially provided a mold box changing method for a concrete block molding machine comprising the steps of:
holding a new mold box, composed mainly of a female type mold and a male type plunger, in a standby position on an inlet path portion at one end of a linear type mold box feed line disposed in parallel to a concrete block molding machine body;
receiving an old mold box-to-be-changed, composed of a female type mold and a male type plunger, the old mold box being separable after use at the concrete block molding machine body, by a receiver;
loading the old mold box on a frame-like carriage located on an orthogonal feed path portion;
the orthogonal feed path being branched at a mid-way of the mold box feed line having a distal end located underneath the concrete block molding machine body,
moving backward the carriage until the old mold box-to-be-changed is brought to a branch path portion of the mold box feed line;
pushing and discharging the old mold box-to-be-changed to an outlet path portion disposed forwardly of the mold box feed line by being pushed by a side surface of a new mold wherein the new mold is pushed and moved by a pusher held in a standby position at one end of the mold box feed line;
loading the new mold box for taking the place of the old mold-box-to-be-changed on the carriage;
elevating upward the carriage with the new mold box loaded thereon to a predetermined location by an elevator-type receiver after the carriage arrives at underneath the concrete block molding machine body;
supporting the mold of the new mold box in the elevated position by a mold support extending from sideways thereof; and
locking a corner portion of the plunger engaged with the mold by a cylinder type split female/male thread type detaching/attaching device having a rotary support shaft extending downward from a press,
said press being elevated downward from an upper location of the concrete block molding machine body,
whereby the mold and plunger of the new mold box are held in vertically separated relation.
From another aspect of the present invention, there is also provided a mold box changing apparatus for a concrete block molding machine comprising:
a roller type mold box feed line spacedly disposed in parallel relation with respect to the concrete block molding machine,
one end of the mold box feed line being defined as an inlet path portion on which a self-travelling type pusher is disposed, an intermediate portion thereof being defined as a branch path on which a self-travelling rail type orthogonal feed path whose a distal end is located underneath the concrete block molding machine body, and the other end thereof being defined as an outlet path portion;
a lifter disposed within a space between opposing rails at a basal end of the orthogonal feed path portion where the branch path portion is located and adapted to bring the mold box-to-be-changed or the new mold box loaded on the carriage into conformity with a feed plane of the mold box feed line or a plane of the carriage;
a cylinder type receiver disposed in a space between opposing rails at a distal end of the orthogonal feed path portion and adapted to elevate upward and downward the mold box loaded on the carriage between a predetermined first position and a predetermined second position;
mold supports disposed along opposite sides of the receiver in a back and forth direction and adapted to retain a lower surface of the mold box by a support arm of a rotary shaft supported on the concrete block molding machine body; and
a split female/male thread type attaching/detaching device pierced into a plunger projecting from a lower surface of a press which lower surface is located on an upper side of the concrete block molding machine body,
the attaching/detaching device having a lockable rotary support shaft actuated by a cylinder,
the mold box-to-be-changed composed of a plunger and a mold being delivered, after use at the concrete block molding machine body, to the branch path portion of the mold box feed line by the carriage,
the used mold box-to-be-changed being automatically discharged from the carriage at the branch path portion and a new mold box for taking the place of the used mold box-to-be-changed being automatically loaded on the carriage.
In the structure described above, each of the mold supports can feed support arms projecting from at least four rotary shafts which are supported in their upstanding postures on the machine body at both outer sides of the receiver to a lower surface of the mold which has been elevated upward by a receiver operatively connected to movement of the carriage.
Further, the split female/male thread type attaching/detaching device constitutes a tightening mechanism which includes a rotary support shaft capable of rotation by a cylinder pierced into the plunger extending downward from the press, a male thread portion having a split engagement groove being disposed at a lower end of the rotary support shaft, an end face of the male thread portion being in the form of an inclination surface cam, a female thread portion having a split engagement groove and provided with an inclination surface cam corresponding to the inclination surface cam of the male thread portion being disposed at the plunger, so that a rotation of the rotary support shaft will cause the first-mentioned inclination surface cam to be contacted, under pressure, with the second-mentioned inclination surface cam.
The lifter may include a link mechanism, which is slidingly moved by the cylinder, and a rail portion having rolls disposed at an upper location of the link mechanism and directing towards the mold box feed line.
As described above, since the orthogonal feed portion for allowing the carriage to travel thereon extends underneath the molding machine body is in the form of a branch path formed at a mid-way of the roller type mold box feed line laid in parallel relation to the machine body, as a preliminary preparation, a new mold box is delivered to and placed in a standby position at one end of the mold box feed line and then, a rear end of the new mold box is connected to the self-travelling type pusher.
For changing the changeable mold box used for shaping a predetermined block, the rotary support shaft projecting from the plunger attached to the press located at the upper location of the machine body is rotated a predetermined angle by the cylinder of the detaching device disposed on the press through a lever. This causes the male thread portion having the split engagement groove and disposed at a lower end of the rotary support shaft pierced into the plunger to rotate to slidingly move this inclination surface cam and the inclination surface cam of the female thread portion having the split engagement groove and disposed on the plunger with respect to each other. And the rotary support shaft comes off (detachment) at the position where a projection and a recess formed on the two split engagement grooves are in conformity with each other. The plunger brought away from the press is engaged with the mold located thereunder, thus forming the changeable mold box.
The changeable mold box thus formed is once slightly floated from the mold support by upward elevation of the cylinder type receiver. Thereafter, the carriage self-travelling on the orthogonal feed portion is advanced. The rotary shaft of the mold support operatively connected to the carriage causes the support arm outward to release its support of the changeable mold box. In that state, the receiver is elevated further downward and the changeable mold box is loaded on the carriage currently located underneath the machine body.
Then, the carriage is moved backward until it reaches the branch path portion of the mold box feed line. When the carriage reaches the branch path portion, the pusher behind the new mold box held in the standby position on one side of the mold box feed line is advanced to the branch path portion where the changeable mold box is pushed by the side surface of the new mold box and discharged towards the front outlet path portion. And the new mold box in the place of the changeable old mold box is loaded on the carriage.
At the branch path portion, the plane of the carriage and the feed plane of the mold box feed line are stepped (i.e., not even). Therefore, when the changeable mold box loaded on the carriage is brought to the branch path portion, the parallel lifter disposed in the branch path portion is actuated to cause the rail portion having the rolls disposed on its upper surface to elevate upward so as to be flush with the feed plane of the mold box feed line. After the new mold box in the place of the changeable mold box is brought to the rail portion having the rolls, the lifter is slightly elevated downward to load the new mold box on the carriage.
Thereafter, the carriage is advanced to underneath the machine body. When the carriage is brought to a predetermined position, the front edge of the carriage contacts an operating element of the mold support thereby rotating the rotary shaft. As a consequence, the support arm projecting from the rotary shaft is opened (escaped) outward to facilitate a smooth upward elevation of the new mold box. When the carriage reaches right above the receiver, the receiver is caused to elevate upward between the rails by the action of the cylinder located at a lower location and the new mold box loaded on the carriage is brought up to a predetermined location. When the carriage is moved backward, the operating element of the mold support is restored under the effect of a spring in operative connection with the backward movement of the carriage, thereby swinging the support arm of the rotary shaft inward. Therefore, the support arm is brought to the lower surface on both sides of the new mold box to support the new mold box. Even after the receiver is retracted downward, the new mold box is held in the predetermined location.
When the new mold box is set in place, the press located at the upper location of the machine body is elevated downward. As a consequence, the male thread portion formed on the lower end of the rotary support shaft of the attaching/detaching device projecting from the lower surface of the press is engaged with the split engagement groove of the female thread portion formed on the plunger which is nested in the upper location of the new mold box, through the projection and recess formed on the male thread portion of the rotary support shaft. In that state, the cylinder on the side of the press is actuated to move the lower portion of the rod so that the lever portion of the rotary support shaft is rotated a predetermined angle. As a consequence, the rotary support shaft integral with the lever potion is also rotated to cause the inclination surface cam of the male thread portion at the lower end thereof to slidingly move on the inclination surface cam of the female thread portion and firmly fixed in the form of wedge tightening.
Finally, the press is elevated upward. By doing so, the work for the attachment of the mold box is completed in which the mold and the plunger are separated in an upper and a lower location of the machine body.